Honestly, if you think about it. You may get up to go and do something that is 30 minutes to an hour, but you have every intention of coming back.
Now I know they made more adjustments to the Duty Finder, but before, it would take me 40-70 minutes to get into Castrum. So I would go AFK for the next 30 minutes. (rr, food, chores, life stuff). Now I may have to sit there, for the whole time, walking about.

I'm not saying I disagree with the implementation. But I would like to see it increased to an hour. Maybe even make it like FFXI, where you can set the time, or even turn it off.